When we bought our place 5-6 years ago, it came with a pool ...(yippee I thought) but I didn't realise how expensive it was to look after a large pond in the garden.
Knowing very little about swimming pools except they look good and inviting (well on the telly they do), I was amazed at the number of issues we have had.
For the last 2-3 years we have had to replace the whole water as this gives me a chance to karture the pool walls and floor. It appears that lime scale is on the pool and that also appears to give algae and things something to hang on to so you can not 'brush' it off. The karturing doesn't appear to get it all off (or maybe I get bored of karturing for a whole day !)
So how can you remove the lime scale and stop it coming back with draining the pool and not having a massive water softener attached !
It is all a question of water balance. France is a big area and some of it has very hard water like yours and a somewhat like mine. What you really don't want to be doing is changing the water every year for fresh water with yet more hardness to deposit. Sorry, it's better to treat the water you have and maintain that at the correct levels. That requires testing and accurate testing. To reduce the hardness you could filter through a reverse osmosis filter but you would need a big one! You could use a water softner which is full of salt which softens via and ion exchange so sodium replaces the calcium (that is the scale) similar to why some report salt water chlorine pools as feeling softer. Or counter the hardness with an increase in the acid level. That would reduce the pH which would then need to be raised without the addition of chemicals or you'll end up where you started. Over a period of days you will then get the hardness lower and the pH stable at a point where the water is neither corrosive or scaling. At that point you want to keep that water in the pool for as long as you can and then maintenance will be so much easier and cheaper.
That is a simplified version but it is what needs to be done to balance the pool and we can look at the alcalinity levels too as in a tiled pool it is important to get the levels corrrect or the grout gets erroded over time as apposed to scale forming.
I too live in a hard water area but do not suffer from scale, When the pool was installed (six years ago) the pool man added a product called anti-calc (?) to the pool followed by the other chemicals to give the correct Ph. Its only during the high summer that we need to add any water at all, during the winter its usually a case that the pool overflows with lovely soft rain water. If you are having problems with high evaporation then you need to use a cover.
Be careful with anti calc, early formulations were often phosphate based and phosphates are like caffine to algae etc. Later versions tend to be based around Ethylenediaminetetraacetic acid (EDTA) which is a metal sequesterant but can help with water hardness. EDTA is slowly used up by chlorine breaking it down so requires frequent topping up. As you said Roger better to top up by harvesting the rain water, that will be dirty until filtered and will use more chlorine initally but it is a solution.
After 9 years in this hard water house I just last week had a sophisticated little water filtration system installed by the husband of the woman who runs the local bio. She has been a font of good local information for me and her English is impeccable, which was a big help when I was just starting to learn la langue.
I installed this system in the garage, where the water main enters the house. It is mounted in such a way that should I move, I can turn two valves to bypass the filtration system, remove the system from the wall and take it with me. My reason for installing this system was finally being fed up with limescale build up on everything to do with water... from toilet bowl, robinets, tub, to dishes and laundry. Also lugging in bottled spring water for drinking and cooking was an expensive proposition.
The new system is brilliant. It has two large filter elements. Within these two housings are several different stacked filters. One must be changed annually, while the other is good for two years. They remove everything that we don't want from the whole house water supply. My biggest concerns were calcaire and chlorine. They are now gone. Glasses and dishes now dry spotless and the difference in my skin and hair after shampooing is pretty dramatic. I am seeing great future health benefits, for the dogs too. I think that there will also be benefits from chlorine free water in the kitchen garden and house plants. This will probably also greatly extend water heater life.
Stop treating the symptoms and go straight after the cause.
The system installed ran Euro 1300.00. I estimate that this is about what I was spending per year on bottled water. Water from this filtration system will fill a pool with sparkling clean, lime-free water. The only other pool concern would be algae control. This will solve your pool problem, as well as all of the annoying effects of hard water in the home.
As I described earlier a water softener and micro filtration unit will do the job. The softener uses salt to exchange calcium for sodium that doesn't coat everything in lime/chalk. The filtration system is ultrafine but not as fine as RO. The unit you have will have a specification for it's work load and through put, if that matches the size of the pool then no issues but usually they cannot cope with the volume of a pool. In The USA a colleague has a truck mounted RO rig that he uses to filter just about everything out of the water rather than waste it and he is busy most of the time.
Oh and you don't want a completely lime free pool, that would be very bad, you need just the right amount generally between 100-300ppm
I would think that adding the proper ratio of lime is preferable to removing the results of excess. I do not have a pool so I am certain that people dealing with their issues are far more knowledgeable than I.
My advice would be to go to a local pool company. They will have the advice and products suitable for your area. I presume you are testing chlorine and pH levels. It is a bit early for me to open my pool in Charente-Maritime but I haven't had scale problems in the past and we have very hard water - 28 degrees.
Dick the biggest issue facing pool owners IS the local pool company. I cannot stress enough the rubbish and mis information these people trot out. They have No understanding of how things work and even more a total lack of understanding of the chemistry involved. The whole idea of the SFN pool section is to finally lay to rest some of the nonsense spoken about pools.
Whatever you do, you need to make sure the pool is thoroughtly clean first and speaking to a pool expert (local or otherwise!) is the best way to go about this, as it will depend on whether you have tiles or a liner.
Then you have a choice of water softeners, electronic water conditioners, or other products that are available. We have a spa pool and used a product called Aquafinesse (there are probably others too), which is environmentally friendly (no chlorine, just the odd Shock treatment), but I do not know whether they have a product available for a large pool - worth a check though as we are big anti-chemical. However, as we learnt rather quickly and as John said , it is also about the PH levels - if they are right the (spa in our case) pool remains relatively balanced. Most of our neighbours have pools and they do seem to be time consuming (which is why we didn't have one!) and they all have different issues to deal with regarding pool care. However, I know they all enjoy using it when the weather is warm!So good luck with getting to grips with it - am sure you will.
In a past life I had to deal with countless pools with limescale deposit... I'm not just talking about a few or x 10; I suppose it would be over 100 pools. Most of those people where given duff advice from their local pool shop, whose ambition it is to have every one who visits walk out with a pale of something or a box of something no matter if they really need it or not. All of which is entirely unnecessary - as John Withall has pointed out, there is a process to limescale removal and it comes with, an understanding of how it was formed in the first place. If you listen to John then you will learn them both and save a lot of time, an incredible amount of effort and a bit of money too.
The standard on knowledge in France on water chemistry in general and pool chemistry specifically is woefully below best practices, so you will not find reliable answers at your 'local poolshop'. What is discussed here will surely redress the balance, I know that in that past life I managed to make a change in the way things are done, introducing photometric testing for example amongst other things. But now John takes over and I have to say is a safe pair of hands - so I suggest that everyone should trust in his advice and you will surely benefit from the results.
As a post note; a most important thing which at this point has to be said: For if you do trust John's (or anybody else's) advice and act on it, enjoying the benefit including the savings and the knowledge for what to do to solve your particular problem, then you should come back onto the Network and say so - GIVE CREDIT WHERE IT IS DUE. Poolshops are only interested in your money, so support the people who care about your pool, on this network
Ok this may get a little controversial.
There is an awfully large amount spoken about with people being anti chemical, it means different things to different people but one thing is certain be it pool or spa it contains chemicals it just depends on which ones.
Aquafinesse products are mainly cleansers that breakdown and remove biofilms, from this MSDS you can see that it is mainly Sodium carbonate (or PH + as we call it) and Disodium metasilicate, which is a floculent and clarifyer which helps remove small particles. The "odd shock" is Chlorine so you have a clean but clorinated pool/spa which is just what we would want but without the higher price tag. Biofilms are more prevalent in spas and hot tubs due to the higher temperatures encouraging bacterial and mould growth so anything that helps with the situation is by way of an insurance policy. Pools being cooler would not really warrant the extra but it's a personal choice.
Thanks everyone for the fast responses....
So I understand the bit about not changing the water each year because I am only putting in hard water - but that did let me have a go at the limescale.
So if I read your reply correctly, probably my best option is to put a water softener device in. I have had a quick look around but have not found much except domestic ones for homes not pools.... can you advise ?